The objective of this proposed research is to elucidate the developmental mechanism of the cerebellar mutant genes in mice, "staggerer(gene symbol, sg)," "weaver(gene symbol, wv)," and "reeler(gene symbol, rl)" in inducing cytoarchitectural alterations in the mutant cerebella. The research plan can be divided into three parts as follows: Research Plan No. 1 is to study the mode of interaction of mutant genes in inducing cytoarchitectural alterations by producing mice doubly affected by neurological conditions and examining their cerebella with an electronmicroscope. Research Plan No. 2 is to determine whether the defect of granule cell migration observed in mutant cerebella lies in the granule cells themselves or in the milieu in which the migration takes place by transplanting granule cells of one mutant to another mutant or normal cerebellum and observing their migration patterns. Research Plan No. 3 is to determine whether chromatographic profiles of tRNA's of mutant cerebella deviate from those of the normal cerebellum by comparing developmental changes in the tRNA profiles of these cerebella.